Electrically-driven hoist.



W. A. BARKER.

ELECTRICALLY DRIVEN HOIST. APPLICATION FILED NOV. 24. 19:3,

1,141,679. Patented June 1, 1915.

2 SHEETS-SHEET I.

Mlnesses;

w, A. BARKER. ELECTRICALLY DRIVEN HOIST. APPLICATION FILED Nov. 2x4.1913. 1,141,679. 1 Patented June 1, 1915.

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'my invention;

turn are, iourn ELECTBICALII Y'DBIVEN HOE}!!- Specification of LettersPatent.

Patent June 1, 1915.

ap lication fi ed. No ember 24, 1913 serial No. 802MB.

" This invention relates to certain improvements in hoisting machines,and particularly to improvements in an electrically driven hoist. Y

. The invention has reference particularly to the arrangement of thehoisting drums, gears, and clutch mechanisms, with respect to a jackshaft to which the power is transmitted in the first place from theelectric motor.

More particularly the invention has as one of its primary objects theprovision of such relationship etween the various mechanisms or elementsabove mentioned that they may be brought together in an extremely simplemanner and within a minimum of space and width of machine.

The invention also has for one of its important objects the provision ofsuch a relationship between the above-mentioned mechanisms that thestrains and stresses occasioned by the sudden clutching or unclutchingof the hoisting drums will be safely and instantaneously taken up orcompensated for by the re iency of an element which may be des gned orpropo tioned with this ob ect in view- Other Qb ects and uses willappear from a detailed description of the invention, which consists inthe features of construction and combinations of. parts hereinafterdescrlbed and claimed.

' In-the drawings: v

Figure 1 shows a plan view of an assembled hoist embodying the featuresof Fig. 2 shows a side elevation of the hoist of Fig. 1; Fig. 3 shows ahorizontal section through the clutch ends of the hoisting drums; andFig. 4 shows a do tailed plan view of one of the drum shifting camblocks- In the. particular embodiment of the mvention which is disclosedin the drawings the hoist is provided with two drums 5 and These drumsare rotatably mounted or journaled on the shafts 7 and 8 ch n led 1n theframe For tin purpose. the frame may be conveniently con} structed as abase portion 10 having thesidostandards 11 and 12 in which the shaftsare gournaled. Each shaft may be provided with a' spool 13 to facilitatecertain classes of hoisting operations.

Driving gears 14: and 15 are rigidly secured to the shafts 7 and 8respectively, so that as said gears are driven they will drive theshafts. Each gear in turn carries a friction cone 16, and said cones areada ted to be engaged by the tapered recesses 1 of the hoisting drumswhen the drums are shifted endwise the necessary amount.

When such engagement is effected the shifted drum will be driven by itsgear thro gh the medium of its friction clutch. In connection with thisfeature it is preferred that each of the main gears be mounted adjacentto the corresponding shaft bearing of the standard 11, so that saidbearing member will take up the end thrust occasioned in securing thefrictional engagement.

I have provided a sim le form of drum shifting mechanism for ringinginto action the friction clutch of each drum. In the particulararrangement illustrated a rotatable block or the like 18 is mountedbetween each drum and the corresponding bearing of the standard 12.These rotatable blocks are provided with cam faces 19 which engagecomplementary faces 20 of the bearings, so that as each block 18 is wungthrough the desired angle it will Shift along the shaft on which it ismounted and thus carry its drum toward and against the correspondingfriction cone 16, Each of the blocks 18 may be conveniently controlledby means of a handle 21 acting through levers and linkages, as bestshown in Fig. 2. These handles are preferably both located to one sideof the hoist, as best shown in Fig. 1.

If desired, ratchet wheels 22 maybe seation, and regardless of whetheror not the work on such outer face. Shafts or rods 25, connected tothese brake bands, extend through the lower portion of the hoist andcarry the foot pedals 26, depression of each of which serves to tightenthe corresponding brake band to set the brake. Helical springs 27 tendto rock the shafts 25 for the purpose of releasing the brake bands andraising the pedals. It is preferred that the foot pedals 26 be mountedat the same side of the hoist as the handles 21 to facilitate control ofthe drums and other mechanism.

From the foregoing it will be seen that the drums and shafts are to berotated by rotation of the gears 14 and 15. For this purpose a jackshaft 27 is extended through the machine from side to side, beingsuitably journaled in the standards 11 and 12. At one end this jackshaft carries a pinion 28, meshing with both of the gears 14 and 15 todrive them both in the same direction.

At its other end the jack shaft carries a sprocket wheel 29, which ispreferably mounted in the same vertical plane, or in alinement with, thedrum shifting blocks 18. A motor 30 drives the jack shaft through themedium of a chain 31 which travels over the sprocket 29. Examination ofFig. 2 will show that the relative positions of the sprocket 29 and themotor sprocket are such that the chain travels beneath the drum shiftingmechanism of the drum 5, and are such that said chain lies between theend of the drum and the standard 12. By thus arranging or locating theparts the chain works or travels in a space which would otherwise beunoccupied, inasmuch as a certain amount of room is necessary toaccommodate the drum shifting mechanisms. It therefore follows that withthis arrangement no additional width of the hoist is necessary for theaccommodation of the chain and sprock ets over that which would benecessary under any circumstances for the accommodation of the drums anddrum shifting mechanisms. It therefore follows that there is a peculiarand definite relationship between the location of the chain andsprockets and the drum shifting mechanisms.

It will be appreciated that with the arrangement disclosed above theentire power for the operation of both of the hoisting drums 5 and 6,and for both of the spools 13, is always transmitted throughsubstantially the entire length of the jack shaft 27 from the sprocket29 to the pinion 28. The jack shaft and the main gears 14 and 15 travelcontinually as long as the motor is in operhoisting load on either drumor spool be continuous or intermittent. Therefore as the drums aresuccessively or intermittentlyclutched and unclutchedfor as hoistingloads are thrown onto or off from the spools, the amount of drivingforce transmitted through the jack shaft fluctuates through very wideand sudden extremes. These sudden and large fluctuations mi ht be verydetrimental to the power transmitting mechanisms unless some means wereprovided for instantaneously compensating to some extent for them. Inthe arrangement illustrated this compensation is afforded by reason ofthe length and torsional resiliency of the jack shaft.

It is well understoodthat the ability of the shaft to twist and absorbenergy or shock in twisting is determined not only upon the material ofwhich it is made and by its diameter, but also by its length between thepoint of application of the twistin'g forces. Therefore in thearrangement set forth herein the jack shaft possesses a maximum oftorsional resiliency, that is, ability to twist between its ends andstore up energy within its material by reason of such twisting,ultimately giving up such energy as it untwists. This is for the reasonthat the maximum feasible length of jack shaft is afforded betweentwisting points by placing the driving sprocket at one end and thepinion at the other. e

It therefore follows that the relationship of parts disclosed herein isnot only such as to accommodate the several elements or mechanismswithin a minimum of space, by having the driving sprocket lying in thesame vertical plane as the drum shifting mechanisms, but that also thearrangement at the same time provides a maximum of resiliency in thejack shaft 'for the reason above set forth.

It will. be understood that although the storing up of energy in thejack shaft, and the subsequent delivery of energy from the jack 'shaftby twisting and untwisting serves to provide a reservoir for energy forequalizing the strains and stresses on the gears and other parts, stillit is not necessary that the shaft should twist or untwist to a largeextent in order to se cure this equalizing effect. In other words, byusing a material of high elasticity, such as steel of the desiredcharacteristics, a com I wish also to emphasize the fact that the Idesirability of making provision for protection of the gears and otherparts against abnormal strains andshocks 1s great in a machine of thiskind in which the driving element, namely,'the motor, is runningcontinually. The conditions in this respect are very different fromthose existin in the case of an intermittently operated driving'element,such for example as a steam engine 1,141,679 a is which is started andstopped accordingly as it is desired to rotate the drum or allow it tocome to rest.

I do not limit myself to the construction herein described andillustrated, except as I may do so in the claims, but I include withinthe scope of my invention any equivalent mechanisms operating inequivalent manners to produce equivalent results.

I claim:

In a hoist, the combination with a stationary framework, of oppositelydisposed sets of bearing journals carried thereby, transverselyextending shafts mounted in said journals and free to rotate in them, amain gear mounted on each shaft between :the

bearings thereof and adjacent to the corre sponding bearing, a windingdrum mounted free to rotate on each shaft between the main gear thereofand the opposite bearing, a friction clutch device between each hoistingdrum and the corresponding main gear,

' shifting mechanism mounted on each shaft between the correspondingdrum and bearing away from the main gears, a jack shaft journaled in theframe work and lying parallel to the aforementioned shafts, a pinion onone end of said jack shaft meshing with both of the main gears, asprocket on the other end of the jack shaft and lying substantially inthe plane of the aforementioned shifting mechanisms, a motor secured tothe framework and mounted to one side of the hoisting drums, a drivingsprocket on said motor lying in line with the sprocket on the jackshaft, and a chain connecting both of the sprockets together andextending between the end of one drum and the framework, and beneath theshifting mechanism WENDELL A. BARKER.

Witnesses:

' THOMAS A. BANKING, Jr.,

FRANCES M. FnosT.

